August 2020

25th Anniversary Special Feature!
Mo-Fi Sounds Great On Your Hi-Fi
Celebrating 35 years of working with many talented engineers, designers, and visionaries.
Article By Shawn R. Britton
Senior Mastering Engineer At Mobile Fidelity Sound Lab

  Anniversaries are an important thing. Ask the person who forgot their own wedding anniversary. Chances are that they didn't forget it again the following year. Congratulations to Enjoy the Music.com for 25 years of audio enthusiasm! My anniversary at Mobile Fidelity Sound Lab will be this August. I started 35 years ago.

"You want to work for a record company?" These two scruffy-looking cats eyed me earnestly. "We need some production guys to make cassettes for us".

I played it cool. "Depends on the pay, I guess". "I mean, I have a day gig at the moment". I was a total record nerd, always cleaning my new LP's and playing them once through to reduce pops and ticks, then transferring them to cassette tape, never to be handled again. I slavishly emulated the logos of my favorite bands and record labels for the J-card insert of the tape box. I made mixtapes for friends that were circulated around our little county. I always got a secret thrill out of hearing one of my tapes played at somebody else's party.

"What's the name of the record company?"
"Mobile Fidelity Sound Lab". Say what?

I had seen Mobile Fidelity's half-speed mastered reissue of MFSL 1-030 Eric Clapton Slowhand LP in a Pacific Stereo Hi-Fi shop up in Santa Rosa, and was blown away by how great it sounded. I tried to buy it on the spot, although it cost about double what I had seen the record sell for in my local store. The salesman breathlessly told me what made the "MoFi" stuff superior. I thought that it might have something to do with the whole Original Master Recording stripe on the top of the record jacket. "Oh, no" he wheezed. "It's not just avoiding generation loss by using the original master tape instead of a copy tape, it's also that they run the record cutting lathe and the tape machine at half-speed instead of at real time, and then it cuts a much more accurate groove". Yeah, I could grok that.

Using my advanced powers of deduction, I said, "instead of 33.3 RPM, that lathe runs at somewhere around 16 2/3 RPM?" "That's weird. Wait... then, like, the tape machine plays back at 7.5 ips if it's originally a 15 ips master tape?" "Yep!"

So, here were these dudes pretending like they were part of the MoFi.

Ha! I knew that Mobile Fidelity was down by L.A., and wasn't likely to be up in our neck of the Redwoods. The duo informed me that they had just moved up to Sonoma County, and were setting up shop in Petaluma. The warehouse racks and security cage were already in place, and the tape duplication facility was due to be running on all cylinders in the next couple of weeks. I went to check out the operation right away.

Turns out they had one hundred and ten rack-mounted JVC KD-A77 cassette decks all recording in real-time on BASF TP 18 Chrome tape stock. I had never seen that many decks in one place before. The techs were wearing white lab coats as MFSL C-106 The Beatles "Rubber Soul" blasted through the playback system console. While they monitored each deck one by one to verify proper recording, I looked around the room and saw rows of 3/4" U-Matic videotapes in these cool 3M shipper-hangers mounted on the sidewall.

I was told that for CD mastering, the U-Matic tapes contained 16-bit digital audio encoding in the "video" portion of the tape, with a longitudinal SMPTE time code striped in one of the two channels that would normally carry audio meant for TV broadcast. The start and stop SMPTE locations for each CD track had to be typed into a log and sent along with the videotape to be replicated into the new Sony/Philips 16-bit Compact Disc optical disc format.

The output of the Sony DMR-2000 video playback machine was run through a Sony PCM-1610 Digital Audio Processor. Multiple video monitors were showing a very unique pattern on the screens.

Mobile Fidelity Tape Duplication Department Polaroid from USA Today photoshoot, circa 1988 with Krieg Wunderlich in the foreground with back to camera while creating a U-Matic digital clone, Shawn R. Britton adjusting azimuth on a JVC cassette deck, and Tori Swenson apparently holding the Studer A80 "SuperMaster" from floating away.

Seemed to me like equipment that any competent mastering house would have. I was very wrong. A whole bunch of the gear that MoFi had brought up from Los Angeles was modified or custom-built by top audio designers in the industry.

Along with the U-Matic system, there were a couple of reel-to-reel tape transports similar to ones I had seen before in a recording studio. I remember a Studer A80 Mark II with a John Curl reproducer amplifier that they called a "SuperMaster", and if memory serves, a Nagra NTA-2S in an elegant stand.

There was also some rather obscure gear along a back wall that seemed to be a digital audio/video system tied to a couple high-end VHS and Beta recorders. Before the advent of the Compact Disc, Sony had developed the PCM-F1 14-bit system that utilized the PCM-100 Digital Audio Processor in the professional market. The Mobile Fidelity "Digital Audio Cassettes" are very rare, with most of our sales shipping to Japan. At the time, I felt that the PCM-100 sounded pretty good for only 14-bit quantization.

There was a test bench with a slew of diagnostic gear. I could not wait to get my filthy paws on all that stuff, not knowing that in just a few short years, I would be schlepping much of this system to the Soviet Union to bring home titles from the much-heralded Melodiya Classical music catalog.

We strolled through the warehouse, where the production department had built out a room with a fireproof safe for the master tapes on loan from the record labels and a King 780 cassette loading machine that injected the BASF tape into the polycarbonate "C-Zero" shells for custom length tapes required by each music program. Once these tapes were recorded up in the "dupe room", they were neatly placed in tubs and then wheeled on carts back to the load room from whence they had originated.

There was an ITI model L-1 BX cassette labeler pneumatic machine that applied the adhesive-backed labels onto the clear shells, then spat them into a tub to be stacked and delivered to the warehouse for collation. If you even looked at it wrong, that thing would misapply the labels at a hellacious rate. Some days I felt like I was within an I Love Lucy scene where Lucy and Ethel go to work in a candy factory, except that I couldn't eat my mistakes. Those polycarbonate shells were damned near indestructible!

I asked if I could see the record cutting lathe, and if Stan Ricker happened to be in. I did not want to disturb The Master while he was working, but once I saw his "SR/2" initials scribed into the lead-out area on my LPs, I had an image of him, a little movie in my head of Stan manning the lathe at half-speed, adjusting levels, equalization, and tape azimuth all at the same time while advancing the leadscrew to make a spread on the fly.

I had promised myself that I would make the pilgrimage down to Chatsworth just to see Stan work. He wouldn't have to talk to me; I would just peer through the glass and watch in amazement while he spun the master lacquer like confectioner's sugar into a gossamer audiophile creation. Hell, now I didn't have to drive all the way to Chatsworth. He was in my virtual backyard!

Neumann SX74 Cutterhead with NiChrome stylus heater wires illuminated from below. The wires resist a small electrical current passing through them, heating up the sapphire, & making for a smoother cut through the nitrocellulose material of the master lacquer. Too little heat = groove wall striations and surface noise, too much heat = lacquer melting under stylus, making groove wall noise and "crackling" sound.

Neumann SX74 Cutterhead with no cutting stylus mounted in the torque tube. Too much downward force while mounting the cutting stylus can "ream out" the torque tube hole, or damage the drive coils and bend the torque tube. Thousands of dollars in repair costs.

I got a strange look from the production manager when I asked about seeing Mr. Ricker and the infamous Neumann VMS70 lathe with the Ortofon DSS821 cutterhead.

He said, "Stan is still down south, man". "All right", I replied. I figured that I could be patient, volunteering for mundane jobs that other people didn't want as a way to learn and have my work be valued. Meanwhile, the production had to continue so I got busy with the tasks at hand.

The U-Matic tapes sent to the CD replicator had to be quality controlled, and all start, stop, and index locations “tight-logged” and typed into a SMPTE PQ code location sheet. The tapes could be scrubbed back and forth by scrolling a jog wheel on a video editing system and listening while watching the audio pattern change on a monitor.

Stan Ricker Passport photo circa 1986, probably right before his trip to the USSR.

Flash forward a few months, and I finally got to meet Stan Ricker in person when I wheeled him up the Studer A80 Preview transport (in Europe, these are known as a "Prelisten" transport). When I brought the Studer into the LP mastering room, Stan came up from underneath the console with several audio cables in his hand. Some seemed to have bare wires on one end, as though he may have yanked them out of something. When I gave him a quizzical look, he just laughed and said in a voice not unlike a pirate, "ah, you don't need those. That was bullshit anyway. It'll sound better without that stuff". We listened to test cuts. He was right. It did sound better.

After that, I called him the "Manic Mechanic". I asked a million questions. If one of them struck him as particularly interesting, he would say with a grin, "isn't that a bag of grapes?"

I asked why the Preview Studer seemed to have two sets of reproducer amplifiers, but no record electronics.

Mobile Fidelity has always had an "all-analog" cutting system, meaning that when a project comes to us on a reel to reel tape, the signal path is completely analog from both the preview playback head/reproducer amplifier to the pitch and depth computer (essentially a device to ensure proper spacing between the cut grooves). The signal path from the program playback head / repro amp through the signal path to the lathe cutterhead is also all analog.

Tape path diagram shows possible tape delay positions (marked in tape ips and platter rotation speed) between "Preview" and "Program" Reproduce heads for proper Pitch and Depth alignment, reducing overcuts/groove crash or liftouts due to vertical modulation.

The tape path can be adjusted depending on the diameter and rotational speed of the desired lacquer cutting. This change in the length of the tape path utilizing guide rollers will cause the audio signal to the program head (and thus the cutterhead) to be delayed with respect to the preview head, maintaining proper groove pitch and depth and avoiding overcuts.

Other cutting systems use a form of digital delay to offset the audio going to the cutterhead.

Tape Reproduce head Azimuth Micrometer. Knurled Azimuth Micrometer makes for precise and repeatable adjustment of playback head azimuth absolutely critical for proper high frequency reproduction and proper phase coherence. For LP mastering, this is a must-have.

The years rolled on, and due to the cratering of the LP format, Mobile Fidelity got out of the vinyl business for a spell, but Stan was never more than a phone call away. He was always gracious about providing technical support or just shooting the bull.

Around 1996, Mobile Fidelity Sound Lab commissioned Tim de Paravicini of EAR / Yoshino fame to custom build us a reproducer amplifier for a Studer A80 Mark II tape transport. In a shootout with several members of the Audiophile press in attendance, Tim's transport proved to have a flat frequency response from 10 Hz to out beyond 43 kHz, an unheard-of benchmark up to that point in time.

Our current LP mastering system, again designed and built by Tim, has extremely wideband frequency response. The cutting chain has unparalleled accuracy from the Studer playback head to the cutterhead.

When we got to work together again at MoFi, Stan explained to me that there are a number of instruments that produce harmonics well above 20 kHz. Percussion instruments in particular, like cymbals, have incredibly extended high-frequency content. As one would expect, many brass instruments do, too. Stan's favorite example was the Harmon trumpet mute, used to great effect by Miles Davis. One of my personal demos for this would be the song "Blue in Green" from the Mobile Fidelity album, Miles Davis Kind Of Blue [MFSL 2-4511]. The harmonics that Miles was able to produce with the Harmon had resonances well beyond 40 kHz. We wanted to have a cutting system that could reliably reproduce that type of content, with no filtering in the signal path to protect the cutterhead.

Stan Ricker taught me his philosophy, with particular attention to a scientific methodology developed over several decades as a respected disc mastering engineer, whether it was calibrating a reproducer amplifier / Dolby decoder, achieving unerring azimuth accuracy through oscilloscope and spectrum analyzer utilization, observing proper polarity or employing minimal to no equalization.

It has been my good fortune to have begun my career with Mobile Fidelity Sound Lab when I did, but it has been my incredible good fortune to have worked with many talented engineers, designers, and visionary product development departments in the last 35 years.

The one guy that I wanted to be taught me how to always do my best, but have fun doing it.

Mobile Fidelity Sound Lab, Inc.
1811 West Bryn Mawr Avenue
Chicago, IL 60660

Website: www.MoFi.com

Studio and Mastering Facilities:
Mobile Fidelity Sound Lab, Inc.
105 Morris Street
Suite 145
Sebastopol, CA 95472